On 02/21/2014 09:45 AM, Caloma Trumica wrote: > Dear all, > > What data are stored in *.igk{n} files? Also, which f90 code controls > the output of the igk files. >
\psi_k(r) = exp(-i r.k) \sum_G u_G exp( -i G.r) = \sum_G u_G exp( -i (G+k).r) The G vectors are sorted on the FFT grid in a regular order, i.e. in unit of reciprocal lattice vectors G_1 = (0,0,0) G_2=(0,0,1) .. G_nx=(0,0,nx-1) G_nx+1=(0,1,0) ... G_nx*ny*nz=(nz-1,ny-1,nx-1) Note that this set of point form a box with the same shape as the reciprocal lattice unit cell (but much larger). However, the condition on the cutoff selects a sphere of valid G points, such as |G+k|^2 < ecutwfc. The file igk (one for each k point) contains the list of G vector such that |G+k|^2 < ecutwfc, sorted in order of increasing |G+k| The list is generated by ./PW/src/gk_sort.f90 and written just afterward in hinit0.f90 (and in many otehr palces in other codes) HTH cheers > Thanks a lot. > -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Universit? Paris 6 +33 (0)1 44 275 084 / skype: paulatz http://www-int.impmc.upmc.fr/~paulatto/ 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2956 bytes Desc: S/MIME Cryptographic Signature Url : http://pwscf.org/pipermail/pw_forum/attachments/20140221/a0f64c48/attachment.bin